Working with old industry friends, Merrill designed a family of small jet aircraft around his engine concept, ranging from a 260-mph single-seater weighing just 760 pounds to a 10-seat executive jet. He called the project Private Jets.

In 1991, a friend introduced Merrill to Donald Douglas Jr., son of the Douglas Aircraft founder. Then 75 and retired from 20 years in the executive suite of the family business, the gruff, no-nonsense Douglas listened intently to Merrill's 45-minute pitch. "He got it immediately," recalls Merrill. A few weeks later, Douglas agreed to use his name and industry contacts to help Merrill raise money. The company was renamed Douglas Private Jets.

Douglas set up meetings with a number of old buddies. There were some tantalizing negotiations, but once again, nothing came of them. Increasingly frustrated with the turndowns, Merrill and Douglas drew up a plan in 1993 to tap a new source: the U.S. government. That June, they gave a two-day briefing to engineers and managers at NASA's Lewis (since renamed Glenn) Research Center in Cleveland. Nice presentation, they were told, but no money available there. Undeterred, the pair went to Washington, D.C., and started knocking on doors. After two years of pleading that included audiences with NASA chief Dan Goldin and FAA boss David Hinson, Merrill and Douglas pulled off what appeared to be a stunning victory: Congress appropriated $37.25 million for a NASA research program based on their Private Jets concept.

The research effort was assigned to the Lewis center and renamed the General Aviation Powerplant, or GAP, program. According to a NASA press release with hyperbole matching that of the flip charts Merrill showed potential investors, GAP's goal was to "reduce the cost of small turbine engines by a factor of 10 and revolutionize the concept of personal air transportation." Just one catch: GAP was to be opened up to bids from the industry. Suddenly Merrill was going up against the big boys again. And there was another problem: Goldin's philosophy that the agency should take care of its "customers"—the established engine manufacturers that it had been working with for years.

Merrill tried to partner with several manufacturers, but in the end, Douglas Private Jets went it alone. Williams International won the GAP contract with its FJX2, a cutting-edge turbofan that worked fine in the test cell but flopped when the company tried to turn it into an engine for the Eclipse 500. It has since disappeared (see "The Little Engine That Couldn't," Oct./Nov. 2005).

"NASA stabbed us in the back," says Merrill. "Instead of an engine for a 200-knot, 20,000-foot lightplane like we proposed, they ended up with an engine for a small business jet that cruised at 41,000 feet. Even if it had worked, it wouldn't have revolutionized a damn thing."

Sour grapes? NASA's Leo Burkhardt, the GAP program manager, confirms Merrill's role in getting the GAP ball rolling. "Gerry's advocacy opened our eyes to the potential of small turbofans," he says. "Gerry made it happen. I give him total credit for that." Burkhardt says he considered Merrill's proposal technically feasible but felt that Williams' design was more advanced. "Of course it was more advanced," retorts Merrill. "That's why it failed. The whole point of our engine was that it was all proven technology, but optimized for the low-and-slow regime."

Don Douglas died in 2004, and Merrill has carried on with occasional help from Douglas' younger brother Jim and other industry friends. He still gives presentations now and then at the Experimental Aircraft Association's annual fly-in at Oshkosh, Wisconsin, and is currently targeting a potential investor in the Persian Gulf. Although Merrill's enthusiasm for his crusade shows no signs of spooling down, he seems resigned to his 40 years of failure. "People get interested, but everywhere you turn, the capital always seems to be committed to other projects," he says. "To people with money, we're just bothersome pissants."

Bruce Holmes, the cerebral former NASA general aviation soothsayer, puts it a bit more delicately. "It comes down to the investment culture these days," he says. "Going from slow little planes to fast little planes really changes the paradigm. That's too unpredictable for most investors."

That's because most investors are cautious by nature, says Richard Aboulafia, an analyst for the Teal Group, an aerospace investment consulting firm in Fairfax, Virginia. "Investors are willing to underwrite incremental improvements, but not great leaps forward like Merrill's," he says. "The [market is] too unpredictable, and that scares them off. You need slam-dunk numbers to attract money, and investors don't see that kind of potential in the lightplane market. They want to see numbers like the bizjet market, which has more than quadrupled in the past decade."